You "expect" why? What is your prediction based on? There is no data to suggest that this will happen. Furthermore, if self-driving cars do take off, they will

You "expect" why? What is your prediction based on? There is no data to suggest that this will happen. Furthermore, if self-driving cars do take off, they will continue to be outnumbered by normal cars for a very long time. It's not even clear that they will or should be the majority.